Gerald, for some reason ARC recommends using their parts, e.g., bias resisters. I don't know why. They only charge a buck so per resister. Selling "matched" resisters can't be a big profit center. So, I would order the resisters from ARC.
As to tubes ... I think the main stream brand is Tung Sol KT-120s, but there may be other KT-120 manufacturers. ARC charges about $100 a tube, which is twice as much as what other reputable vendors, such as Upscale Audio and so forth. I've gone both ways with tubes. I don't think ARC's KT-120s sound better than anyone else's KT-120s.
But there are two advantages going with ARC. One ... it has been my experience that ARC does a better job of matching tubes. An ARC matched pair biases very closely.
Two, if a tube arcs within 90 days of purchase, I believe ARC will replace it. They may also repair any damage caused, e.g., open bias resister. I'd check the last point.
Btw, I used to own the VS-115. Traded up for a Ref 150. I think the VS-115 is a super-duper amp. Enjoy.
Bruce
